We set up their nest up there so that Maui won't go ballistic constantly; he wants to be involved but they don't want him to be, and he was going into 'attack anything that moves' mode. Maui can't get up there and so this works well.
Yes and no. Cockatiels, like chickens, can lay without being fertilized. Luna and Vinnie are mates but I am not certain their eggs are fertilized, and since they often leave the eggs unattended for a time, they're never going to hatch. They're not the best parents, but they do nest and they do try, and we do our best to accomodate their instincts.